A conventional latch for luggage or pocketbook as disclosed in U.S. Pat. No. 4,934,162 by Ulf Rasch taught a mechanism for preventing inversion (an upside down) of the luggage by forming an outwardly open cup 13 within the spring 4 defining a cavity holding a ball 14 in the cup 13 and by forming a projection or offcenter tongue 15 in the button 3 so that when inverting the luggage as shown in his FIG. 4, the projection 15 of the button 3 will be retarded by the ball 14 to prevent an unexpected opening of an inverted luggage.
However, such an inversion preventing means still has the following drawbacks:
1. The cup 13 has an outward opening so that the ball 14 may be easily escaped from the cup 13 into a spring chamber retained with the spring 4 to lose its inversion preventing effect.
2. When turning the luggage upside down, the ball 14 may be frictionally retarded by the transversely protruding projection 15 to be unable to reach a lower bottom portion in the cup 13 as shown in his FIG. 4, thereby influencing an inversion prevention effect thereof.
3. Even inverting the luggage as shown in his FIG. 4, a depression of the button 3 to inwardly strike the projection 15 on the ball 14 may possibly or accidentally bias the ball 14 upwardly into an upper portion in the cup 13 so that the projection 15 will no longer be retarded by the ball 14 to thereby lose its locking effect under an inverted condition.
The present inventor has found the drawbacks of such a conventional latch for luggage and invented the present latch having a precise inversion preventing means.